Die for auger-blanks.



No. 740,936. v PATENTED 100T. s, 1903.

I. W. SMITH. DIE FOR AUGER BLANKS.

APPLICATION FILED APR. 22, 1903.

no mm.

well as accurate external diameter, and a Patented October 6, 1903 IVAN \V. SMITH, HOLYOKE, MASSACHUSETTS, ASSIGNOR'TO FORD AUGER BIT COMPANY, OF HOLYOKE, MASSACHUSETTS, A CORPORATION.

DIE FOR AUGE'R-BLANKS;

s'rncrrzcn'rron formingpart of Letters Patent no. 740,936, dated October'S, 1903.

Application filed April 22, 1903.

To all whom, it rmty concern:

Be it known that I, IVAN W. SMITH, acitizen of the United States of America, residing at Holyoke, in the county of Hampden and State of Massachusetts, have invented new and useful Improvements in Dies for Auger- Blanks, of which the following is a specification.

This invention relates to the manufacture of angers and like tools having a spiral form, the object of the invention being to provide means for forging a tool-bodyof spiral form from a straight bar of metal; and a further object is to provide means for producing a tool-body of this character the greatest thickness of which, measured radially thereof, shall be less than the radius of the tool-body.

It is well known that tovget a proper clearance in angers, bits, &c., it is desirable that the thickness of the metal at any part of the spiral body of the tool should be less than the radius of the tool as a wholethat is, that the crosssectional area of the spiral groove should exceed that of the metal remaining. This would provide a tool which if viewed axially would appear to have a hole. centrally through it. Heretofore ithas beeu the practice to give the bitthe requisite spiral form by bending a straight fiat bar to the required shape in a proper device for the purpose, then by means of a rotating cutting or grinding tool cut away the body at the lowest point of the resulting spiral groove to reduce the area of the metal as compared with the area of said groove,as above set forth. This necessitates handling several times and involves more orless expense. Furthermore, it necessitates truing up the spiral after bending, which latter operation does not leave the tool in proper shape to be finished.

By means of the improved die which form the subject of this applicatiomthe body of the bit maybe forged from a straight bar in the spiral form, which heretofore it has only been possible to attain -by means of operations performed thereon after it had been practically roughed out- -that is to say, by means of these dies the required cross-see tional area of the body and a uniform twist are both obtained in the forging operation, as

she: No. 158,776. (No model.)

finished product so straight as to be ready for the finishing operations when it leaves the hammer.

In the drawings forming part of this application, Figure 1 is a longitudinal section of a pairofdiesembodying this invention, showing a portion of an anger inv its relation to the dies. Fig. 2-is an end elevation of the dies in their closed position. Fig. 3 isa plan view of the operative surface of the upper die. Fig. 4 is a similar view of the lower die.

In carrying out this invention two dies, an upper and a lower, (indicated, respectively, by a and 19,) are provided, as usual, which are substantially rectangular in cross-section, there being a semicircular groove 0 running centrally through each dielengthwise thereof. The radius of the groove 0 equals the radius of the bit d. In the lower die I) there are two transversely-located ribs e, whose position is diagonal to the groove 0,-and the degree of inclination of which relative to the axis of the bit determines the pitch of the spiral on which the bit is formed. These ribs are rounded at their upper edges, as shown, and between these edges and the bottom of the groove 0 in the upper die the body of the bit is formed.

The upper die 04 has formed thereon a rib f, similar in all respects to the ribs e, except as to the direction of its inclination, which is opposite-to that of said ribs when in its inverted position, as it is in the hammer, and

of course it has the same pitch and is so located on this die that when the two dies are brought together in the hammer the ribf'will extend diagonally between the opposite end of the ribs e and come in contact with the body of the bit at a point centrally of the groove 0 and midway between the two ribs 6. The rib 'c and the rib f each project beyond the meeting edges of the dies a certain distance, as shown in Figsrl and 2, whereby the metal between the tops of the ribs and the bottom of the groove in the opposite die is given the required thickness. The degree of this projection may be variedaccording to the requirement of the construction, some bits being made with more clearance than others. Thus a bit forged in these dies if looked at endwise would apparently have a circular passage axially therethrough, (indicated by the dotted circle 9 in Fig. 2,) as though the spiral had been formed by winding the body around a core having the diameter of this circle.

The spirality of the bit is of necessity determined by the pitch of the rib e, the hot metal being hammered into the space between the ribs as the bit is slowly rotated, and each portion of said body is likewise exteriorly flattened in the bottom of the groove 0, the reduction of the body taking place simultaneously between the operative edges of the three ribs and the bottom of the grooves c in the two dies.

Having thus described my invention, what I claim, and desire to secure by Letters Patent of the United States, is

1. A pair of dies for forging spiral forms, each having a longitudinal semicircular groove in the face of the die extending from one end to the other thereof, said dies comprising a lower and an upper die; two paral lel ribs extending diagonally across the groove in the lower die, and projecting above the face thereof, one rib extending diagonally across the groove in the upper die in a direction opposite to said two ribs in the lower die, when the dies are face to face, the rib on said upper die also extending beyond the plane of the faces of said die.

2. A pair of dies for forging spiral forms comprising an upper and a lowerdie each having a longitudinal semicirculargroove therein extending from end to end thereof, the radius of said grooves being equal to the radius of the tool-body to be formed; two ribs diagonally located in the groove of one of said dies, and one rib diagonally located in the groove of the other die, and also diagonally relative to the two ribs in the first-named die, the operative edges of all of the ribs being substantially parallel with the meeting faces of the dies and projecting beyond these faces.

IVAN W. SMITH.

\Vitnesses:

WM. H. OHAPIN, K. I. OLEMoNs. 

